package clientapi_test

import (
	"net/http"
	"net/url"
	"testing"
)

type hierarchyResult struct {
	Rooms []struct {
		RoomID           string           `json:"room_id"`
		Name             string           `json:"name"`
		RoomType         string           `json:"room_type"`
		JoinRule         string           `json:"join_rule"`
		NumJoinedMembers int              `json:"num_joined_members"`
		ChildrenState    []map[string]any `json:"children_state"`
	} `json:"rooms"`
	NextBatch string `json:"next_batch"`
}

func (h hierarchyResult) ids() []string {
	out := make([]string, 0, len(h.Rooms))
	for _, r := range h.Rooms {
		out = append(out, r.RoomID)
	}
	return out
}

func (ts *testServer) hierarchy(acc account, roomID, query string) hierarchyResult {
	ts.t.Helper()
	rec := ts.get("/_matrix/client/v1/rooms/"+url.PathEscape(roomID)+"/hierarchy"+query, acc.AccessToken)
	expectStatus(ts.t, rec, http.StatusOK)
	return decode[hierarchyResult](ts.t, rec)
}

// addChild puts a room into a space.
func (ts *testServer) addChild(acc account, spaceID, childID string, content map[string]any) {
	ts.t.Helper()
	if content == nil {
		content = map[string]any{}
	}
	if _, ok := content["via"]; !ok {
		content["via"] = []string{"warp.example"}
	}
	rec := ts.put("/_matrix/client/v3/rooms/"+url.PathEscape(spaceID)+"/state/m.space.child/"+url.PathEscape(childID),
		acc.AccessToken, content)
	expectStatus(ts.t, rec, http.StatusOK)
}

func (ts *testServer) createSpace(acc account, name string, public bool) string {
	ts.t.Helper()
	body := map[string]any{"name": name, "creation_content": map[string]any{"type": "m.space"}}
	if public {
		body["preset"] = "public_chat"
	}
	return ts.createRoom(acc, body)
}

func TestSpaceHierarchy(t *testing.T) {
	ts := newTestServer(t, nil)
	alice := ts.register("alice", "correct-horse-battery-staple")
	bob := ts.register("bob", "correct-horse-battery-staple")

	space := ts.createSpace(alice, "Space", true)
	sub := ts.createSpace(alice, "Subspace", true)
	general := ts.createRoom(alice, map[string]any{"name": "General", "preset": "public_chat"})
	random := ts.createRoom(alice, map[string]any{"name": "Random", "preset": "public_chat"})
	secret := ts.createRoom(alice, map[string]any{"name": "Secret"})
	deep := ts.createRoom(alice, map[string]any{"name": "Deep", "preset": "public_chat"})

	ts.addChild(alice, space, random, map[string]any{"order": "b"})
	ts.addChild(alice, space, general, map[string]any{"order": "a", "suggested": true})
	ts.addChild(alice, space, sub, nil)
	ts.addChild(alice, space, secret, nil)
	ts.addChild(alice, sub, deep, nil)
	// A child event with no via is a removed child.
	removed := ts.createRoom(alice, map[string]any{"name": "Gone", "preset": "public_chat"})
	ts.addChild(alice, space, removed, map[string]any{"via": []string{}})

	// Alice is in every room, so she sees all of them: the root, its
	// children by order and then by timestamp, then the subspace's child.
	all := ts.hierarchy(alice, space, "")
	want := []string{space, general, random, sub, secret, deep}
	if got := all.ids(); !equalStrings(got, want) {
		t.Fatalf("alice's hierarchy = %v, want %v", got, want)
	}
	if all.Rooms[0].RoomType != "m.space" || len(all.Rooms[0].ChildrenState) != 4 {
		t.Errorf("root = %+v, want a space with four live children", all.Rooms[0])
	}

	// Bob is in nothing: the invite-only room is hidden from him.
	if got := ts.hierarchy(bob, space, "").ids(); !equalStrings(got, []string{space, general, random, sub, deep}) {
		t.Errorf("bob's hierarchy = %v", got)
	}

	if got := ts.hierarchy(alice, space, "?max_depth=1").ids(); !equalStrings(got, []string{space, general, random, sub, secret}) {
		t.Errorf("max_depth=1 = %v", got)
	}
	if got := ts.hierarchy(alice, space, "?suggested_only=true").ids(); !equalStrings(got, []string{space, general}) {
		t.Errorf("suggested_only = %v", got)
	}

	// Paging two at a time walks the same order.
	var paged []string
	from := ""
	for range 10 {
		query := "?limit=2"
		if from != "" {
			query += "&from=" + url.QueryEscape(from)
		}
		page := ts.hierarchy(alice, space, query)
		paged = append(paged, page.ids()...)
		if page.NextBatch == "" {
			break
		}
		from = page.NextBatch
	}
	if !equalStrings(paged, want) {
		t.Errorf("paged hierarchy = %v, want %v", paged, want)
	}
}

func TestSpaceHierarchyAccess(t *testing.T) {
	ts := newTestServer(t, nil)
	alice := ts.register("alice", "correct-horse-battery-staple")
	bob := ts.register("bob", "correct-horse-battery-staple")
	carol := ts.register("carol", "correct-horse-battery-staple")

	private := ts.createSpace(alice, "Private", false)
	rec := ts.get("/_matrix/client/v1/rooms/"+url.PathEscape(private)+"/hierarchy", bob.AccessToken)
	expectStatus(t, rec, http.StatusForbidden)

	// A restricted room is visible to the members of the room it lets in.
	space := ts.createSpace(alice, "Space", true)
	restricted := ts.createRoom(alice, map[string]any{
		"name": "Members only",
		"initial_state": []map[string]any{{
			"type": "m.room.join_rules", "state_key": "",
			"content": map[string]any{
				"join_rule": "restricted",
				"allow":     []map[string]any{{"type": "m.room_membership", "room_id": space}},
			},
		}},
	})
	ts.addChild(alice, space, restricted, nil)
	expectStatus(t, ts.post("/_matrix/client/v3/join/"+url.PathEscape(space), bob.AccessToken, map[string]any{}), http.StatusOK)

	if got := ts.hierarchy(bob, space, "").ids(); !equalStrings(got, []string{space, restricted}) {
		t.Errorf("a member of the space sees %v, want the restricted room too", got)
	}
	if got := ts.hierarchy(carol, space, "").ids(); !equalStrings(got, []string{space}) {
		t.Errorf("a stranger sees %v, want the space alone", got)
	}
}

func TestRoomSummary(t *testing.T) {
	ts := newTestServer(t, nil)
	alice := ts.register("alice", "correct-horse-battery-staple")
	bob := ts.register("bob", "correct-horse-battery-staple")
	public := ts.createRoom(alice, map[string]any{
		"name": "Lobby", "topic": "Say hello", "preset": "public_chat", "room_alias_name": "lobby",
	})
	private := ts.createRoom(alice, map[string]any{"name": "Private"})

	for _, target := range []string{public, "#lobby:warp.example"} {
		rec := ts.get("/_matrix/client/v1/room_summary/"+url.PathEscape(target), bob.AccessToken)
		expectStatus(t, rec, http.StatusOK)
		body := jsonBody(t, rec)
		if body["room_id"] != public || body["name"] != "Lobby" || body["topic"] != "Say hello" ||
			body["membership"] != "leave" || body["join_rule"] != "public" || body["room_version"] == nil {
			t.Errorf("summary of %s = %v", target, body)
		}
	}

	rec := ts.get("/_matrix/client/v1/room_summary/"+url.PathEscape(private), bob.AccessToken)
	expectStatus(t, rec, http.StatusForbidden)
	rec = ts.get("/_matrix/client/v1/room_summary/"+url.PathEscape(private), alice.AccessToken)
	expectStatus(t, rec, http.StatusOK)
	if jsonBody(t, rec)["membership"] != "join" {
		t.Errorf("alice's summary of her own room says membership %v", jsonBody(t, rec)["membership"])
	}
}

// children_state is required on every room /hierarchy returns, an empty
// list for one with no children: clients that parse the response strictly
// (the famedly Dart SDK) fail on a room without it.
func TestSpaceHierarchyEmptyChildrenState(t *testing.T) {
	ts := newTestServer(t, nil)
	alice := ts.register("alice", "correct-horse-battery-staple")
	space := ts.createSpace(alice, "Empty space", false)
	room := ts.createRoom(alice, map[string]any{"name": "Leaf"})
	ts.addChild(alice, space, room, nil)

	rec := ts.get("/_matrix/client/v1/rooms/"+url.PathEscape(space)+"/hierarchy", alice.AccessToken)
	expectStatus(t, rec, http.StatusOK)
	raw := decode[struct {
		Rooms []map[string]any `json:"rooms"`
	}](t, rec)
	if len(raw.Rooms) != 2 {
		t.Fatalf("got %d rooms, want the space and its child", len(raw.Rooms))
	}
	for _, r := range raw.Rooms {
		children, ok := r["children_state"].([]any)
		if !ok {
			t.Errorf("%v: children_state = %#v, want a list", r["room_id"], r["children_state"])
		}
		if r["room_id"] == room && len(children) != 0 {
			t.Errorf("the leaf room has children_state %v", children)
		}
	}
}